This invention relates, in general, to disposable cartridges such as are commonly used for local anesthetics and are commonly used in syringes having plungers at one end and double-ended needles at the other so that the plunger forces the cartridge forward onto the needle, thereby perforating its seal and permitting its contents to be expelled to the other end of the needle. In particular, the invention relates to an improved seal at both ends of the cartridge so as to permit sterilization of the same while at the same time preventing any leakage or contamination of the contents thereof.